Chapters Transcript Mechanial Thrombectomy Options for DVT Course: Venous Thrombosis Update 2024 Change gears a little bit, um, I talk about mechanical thromb thrombectomy options for uh DBT. Now, Doctor Sadek and others in the first session have touched upon this, but I think it's one of the exciting things about this field, it's, uh, it's technology that drives a lot of, uh, uh, sort of innovation and change in practice patterns, and I, and I'm gonna talk to you about a couple of devices and, and strategies. Um, here's some disclosures, um. You can see the ART trial. This is a trial that I think everyone should become very familiar with. We've heard about it now twice. You're gonna hear about it the third time now. Uh, this has kind of been, uh, it made a big splash because as you know, uh, we didn't really know what to do with patients who came in with the cable DVT, um, uh, there was a big push to try to treat these patients aggressively with catheter directed thrombolysis, but that carried the risk of bleeding as Dr. Berland just showed. And I can tell you after you see one intracranial bleed from TPA to treat leg swelling, you'll never want to see it again. So it's uh certainly a daunting problem. Here's the results in brief of the trial. You'll you'll see that you have no change. This was a negative trial. There was no change in PTS or post traumatic syndrome when you compared, um, um, pharmaco mechanical thrombectomy to the control group, and so this is a negative trial, um, but you did have increased bleeding. Again emphasizing the the the dangers of giving thrombolytics, uh, there was some improvement in some of the severity, but again with regard to the out the end point of PTS there was no difference. So where does that leave us? Um, how can we avoid the risk of bleeding? And one way to do it is just with strict mechanical thrombectomy. Avoiding TPA pharmaco cat gives some TPA mechanical without it. The Androjeet device here is a device that actually uh is introduced and using a sort of this jet Bernoulli principle of jet can, uh, sort of aspirate, disrupt the acute clots, suck it back into the catheter, and you can see the machine there and this is quite effective, but as Doctor Saek mentioned, I'm not gonna. Repeat these slides uh at length, but there was some concern about this device because of the risk of renal failure and sort of uh hemolysis that can occur, uh, transient thank goodness but um these are slides you saw this morning, so I'm not gonna spend too much time, but you can see that there was in fact some kidney failure associated with these 100 patients when they use the Androjet versus uh um a cathode directed therapy. The penumbra uh is another platform which I'm gonna spend a little time talking about. This is an aspiration technique, and I should mention that a lot of these catheter techniques can give adjunctive TPA at the time in a local way. You can let it dwell in the clot. You can go take a break for 20 minutes, come back after it's taking some action, and then suck it out a little different than systemic TPA, right? But nonetheless there is some risk there. So you can use this without TPA or with TPA. And this is a device that's essentially a suction catheter with a little separator. You see a little olive tip on a on a wire that can use almost like a reamer and it can sort of mechanically disrupt the clot as you aspirate it into a into a uh a tubing. The machine or the pin number engine which you see here is sort of a clever way of. Smart in in an intelligent way, um, detecting when the catheter is in clot. So when it's in clot, it will aspirate and when it's not in clot, it will have intermittent aspiration. And this is done through microchip sensors of the machine there and it's actually aim is to minimize blood loss because if you can imagine putting one of these catheters into the the circulation and hoping that you're sucking out clot is all fine and well as long as you're not sitting in a in a free flow patent vessel where you're just aspirating a tremendous amount of blood. So there's a continuous suction that can an on off switch. You have this intelligent aspiration that detects when you're in the thrombus versus not, and it's pretty simple set up, uh, and you can see here some of the aspiration uh efficiency with the different generations of catheters as they increase in size, they have some torque ability and there's sort of an evolution in the technology within this company. The newest technology in that company per number is called Lightning Flash. And I won't be believe you with the the the differences, but I will tell you that it's a bigger, it's a 16 French. It has great application for not just DBT for, but for PE, uh, it does still have that separator which has to be used with some caution, especially in the pulmonary artery, um, but, uh, it, it can be very effective in aspirating acute or subacute thrombus. The IAE is another um company that is a, a big player in this space of mechanical thrombectomy and unlike an aspiration system like you just saw with the uh penumbra, it has sort of a chorine uh stent that engages the thrombus and then as you pull back the entire system, the thrombus is sort of extracted and captured into the a a trailing bag or if you will, that then is retrieved from the patient after a number of passes, you can actually clean out the vein. Um, there is also uh different iterations of this, where you can actually, um, and you can see there's a cartoon showing the corn element with the collection bag that trails and then it has a sheath with a funnel that extracts it from the patient. Uh, here's a case. You can see here some of the chronic or not chronic, acute or subacute thrombus. And after extracting it with the clot triever as is shown here, you have a patent vein. And this is some of the material or thrombus that can be removed from the patient. So there are, there are some clout, which is the uh trial for NRA, um, we were a site here. uh, Doctor Sadek mentioned this a little bit, but this was a, a multi-center uh prospective, uh, registry that looked at safety and efficacy of the clot triever for acute DVT. Notably acute is the key word here because these are clots that have been present for 14 days or less by history, and I'll, I'll mention a little bit about that because in fact many of these clots have been there perhaps longer. Here's some of the highlights of the clout study. Again, 250 patients, and you can see that it has um significant improvement in post-thrombotic syndrome, symptoms, pain, quality of life at 6 months, and there's an even more recent publication showing 2 years out that this is uh quite effective. Here's some of the immediate and sustained improvements by um quality of life and by uh circumference and um you'll see here that uh there's a pain rating score that at baseline at 6 months people have significant improvement clinically after trying to remove this DVT in the acute setting all without TPA. you can see ultrasound showing patency of the veins. Um, I mentioned earlier with Doctor Mars earlier about the fact that many of these studies don't comment on valvar function. They all talk about patency, but I'm curious that they don't necessarily comment on that, and that's something that perhaps the room for future research. Um, you can see that duplex does in fact show improvement at 6 months. And this is the Volalto score, which you're all familiar is a scoring system we use to clinically assess uh improvement and you can see that um that post clot triever use, you have a significant improvement in Volalta score compared uh to um pre baseline. So I mentioned that all these devices are best suited in the acute setting and why is that? It's because when you have a DVT, it's like a piece of jello in the vein. It's soft, it can be sucked out with a straw, it can be pulled out with a catheter, but as that jell-o, as that DVT matures. It becomes more scarred and more of a cast, and that becomes a very, very difficult thing to treat even with me certainly with TPA it's not not gonna be a candidate, but even mechanically it's very difficult to disrupt. There are some new late breaking technologies that sort of disrupt it mechanically, but it's best to get to the clot early and this is important clinically. So if you see a patient with a DVT in your office, it's best to, especially if they're young, to perhaps refer them early. For evaluation because if I see a patient who had DVT 3 months ago versus 2 weeks ago, it's going to impact my algorithm. I'm gonna be much more likely to tell them I'm gonna have a successful outcome if it's a fresh DVT versus if it's chronic. But does chronicity matter? Well, here's a study that we conducted, uh, based on the cloud cloud uh registry, and you can see that there's the acute, subacute and chronic. They have a different appearance when you remove this clot, you visually inspect it and it looks whiter, looks more fibrous when it's chronic versus when it's acute, it appears more dark and gelatinous. Symptom duration, the acute patients who presented with 2 weeks of symptoms with the majority, 70%. When you do pre-thrombectomy imaging, you're looking with an ultrasound and something we talked about with Doctor Marks, you can not just detect DVT with an ultrasound, but you can detect the chronicity. It becomes hyperechoic when it's more chronic, you see chronicity, whereas if it's acute, it may be plump, the the vein may be plump, full, and very dark appearing when it's acute. So you have the pre-thrombotic imaging, you have the symptoms, and yet when we take the clot out, you can see that you, you actually have much more chronic clot than you would have imagined or predicted based on symptoms and or duplex. So you're extracting clot that you thought was acute but in fact had been there perhaps much longer. 50% of thrombus was more chronic than expected, and here's again some visual representations of acute on the left to chronic being white and fibrous appearing on the right. You can see you can stretch quite a bit of this thrombus. So the cloud registry shows excellent safety and efficacy in the real world for subacute, acute, and also perhaps chronic. Now I say this with parenthesis because the true chronic that comes in 5 years after DVT is not the patient we're talking about. I'm simply saying that in the acute setting there is some chronic clot there that's perhaps underappreciated. So should we intervene early now that we have newer technology avoiding the risk of TPA? You heard about this controversy with the track trial and that's what really swung the pendulum away from early intervention because we all got scared of bleeding and we all recognized that perhaps there wasn't any improvement with regard to PTS. So why should we offer these new technologies? Well, when we do, this is a nice paper by Steve Bromwitz, who was one of the investigators of cloud. They took propensity matched patients from the track trial and from the clout registry. So they took these two studies propensity match the patients, try to give them some equipoise and really, really compare them and see whether if you're taken those patients from a tract and if you only had not then what you have now this TPA free intervention treatment, how would they fare? Here you can see the 499, the clout 337, the tract. At the end you had this propensity matching uh based on age, sex, race, etc. martyr score and you matched 130 to 130 patients in each of these arms and you can see some of the baseline characteristics and you'll notice that after matching on the right side, you have a good subset of patients, 130 to 130. And how effective is mechanical thrombectomy? That's just the clot triever, no TPA versus the pharmaco mechanical thrombectomy that was used in a tract. You can see here that when you use matched ilofemoral DBT, um, you can see that the proportion of patients with greater than 75% or even 100% thromus removed post procedure by marter score, which is from the core lab, is improved, uh, with, uh, mechanical thrombectomy. You're clearing much more than you would if you just use the TPA. And on the right side you see the Val score is also much improved in the cohort that received mechanical thrombectomy compared to the attract patients. So there's clearly an impact to this new technology. How about procedural outcomes? Sorry about the typo on the title there, but you can see here that thrombolytic use, uh, in the mechanical thrombectomy was a single session. This is something we haven't talked about when you give TPA, oftentimes you have to put people in the ICU and recovering for a night and let the drug drip in overnight. That has its own risk for bleeding, but also logistically becomes very problematic. You have to bring them back to the operating room or the interventional suite the next day. When you use the clot triever or a mechanical device like this, you can off the table, you're one and done. And so you can see the results here when you propensity match them that with the clot triever you were able to do them in one session versus when you use the attract patients, they were done in more than one session. Um, you can see here, a single session thrombolytic use of course, and when you look at the ICU state, all these are meaningful differences these two courts of patients. So when is a DVT or surgical emergency? I think this is a good example of how mechanical thrombectomy, um, plays a good, a good role. Uh, just, uh, we have another couple of cases later, Doctor Sadek will present, but this is a 64 year old woman morbidly obese. You can see some of her risk factors. She's had an IVC filter placed because she had a PE in the past, multiple DVTs. She's had some metastatic cancer. Clearly she has a lot of risk for, um, for BTE. And she comes in, uh, with having held her Xarelto after laparoscopic procedure, also morbidly obese. I mean, the laundry list goes on and on, um, and she comes in with this picture and you heard about like major earlier with Doctor Sadek. This is what I would consider really a surgical emergency. This patient has not just venous but arterial compromise as a result of very advanced venous engorgement or or or inclusive uh problem. Legs are cool to touch, purple modeled, uh. Absent signals in the feet, fatally palpable femoral pulses. This is sort of a surgical emergency. I, I put it up because I guess, you know, when we talk about DVT, PE always comes to mind as the, as the big, you know, the, the big risk, but there are other sort of less common risk factor, uh, uh, risk, uh, situations that are that are should be thought of. Um, like measures can be either Alva Jones. Doctor Sadek mentioned this, and the result of very advanced venous engorgement or, or, or exclusive, uh, problem. Legs are cool to touch, purple modeled, uh, absent signals in the feet, faally palpable femoral pulses. This is sort of a surgical emergency. I, I put it up because I guess, you know, when we talk about DBT, PE always comes to mind as the, as the big, you know, the, the big risk, but there are other sort of less common risk factor, uh, uh, risk, uh, situations that are, that are should be thought of. Um, lag measure can be either Alva dos, Doctor Sadek mentioned this, and you see as the sinosis worsens, venous congestion worses, you develop these skin changes, motor sensory changes, it becomes an arterial problem. Here's the um the uh CAT scan, and here's where I'd like to get axial imaging on these patients to see the extent of the thrombus and you can see here that the IVC itself has been occluded. There's been a stent placed on the left side, perhaps from aerners, not clear, that is also included and this is a patient then um you have some concern for trying to. Uh, quickly clear this clot, um, uh, preferably without TPA, uh, we went from the right IJ to place these discs that can be used almost like IVC filters to protect against distal embolization when we try to clear the clot from below. And, uh, with bilateral pop main axis you can introduce a flow triever which is a sort of larger version of the clot triever that allows you to suck um some of the clot out. And um you can also, as mark, you can actually milk the leg with butane elastic uh sort of uh a wrap to try to get some of the clot to clear. There's the clot in the IVC on the left. Coming from below, you're sucking that clot out and you see above you have these sort of discs that serve to temporarily protect, almost like a filter, protect against any uh disbilization and there's some of the specimen again that you can extract. So before and after you can see a very dramatic appearance uh after uh decreased swelling, but more importantly, the color is returned to normal. So you can see the mechanical thrombectomy using a number of different devices have promising results. I think minimizing blood loss is still something we have to struggle with because uh there's no doubt that as these cases, uh, despite some of the intelligent sort of, uh, engines for the penumbra and even with the clot triever, uh, you have some risk of blood loss. But nonetheless, I think you can avoid lytics. I think this is really the biggest advance here. You can avoid the risk of TPA. Um, there's also hospital logistic issues that are improved length of stay, ICU stay. And I think it can be really li limb saving, right? So patients who have like major in particular, um, but aside from those real sort of surgical emergencies, if you will, I think the, the big exciting, um, sort of news here is that, um, the track trial, although an important trial, um, I think with new technology is going to become obsolete in my opinion. There's gonna be a lot of uh push now for the pendulum to swing the other way now that you have options to treat some of these patients, um, uh, without TPA. Now you can also use in the upper extremity, um, and I, I didn't put this up there, but there's, there's a number of papers looking at treating Paget Schroeder's. Doctor uh Bloomberg had talked about this before about um effort induced thrombosis as lavian vein, and we can also treat those, uh, with suction aspiration and, and before we do a ribber section, so. We'll take more questions at the end, but thank you for your attention. Published April 19, 2024 Created by Related Presenters Thomas Maldonado, MD View full profile
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